I’m in some busy fake IRC channels. In real IRC channels, people don’t join and part like crazy. But when you join channels that are actually other networks like Discord, then there is a lot more joining and parting. And you don’t want to enable rcirc-omit-mode for each and every one of them by hand. Luckily, I found this useful snippet by Giorgos Keramidas:

(add-hook 'rcirc-mode-hook
(lambda ()
;; rcirc-omit-mode always *toggles*, so we first 'disable' it
;; and then let the function toggle it *and* set things up.
(setq rcirc-omit-mode nil)
(rcirc-omit-mode)))

Why doesn’t rcirc-omit-mode take a parameter like all decent minor modes?